Type IV pili (T4P) are surface-exposed fibers that mediate many functions in bacteria, including locomotion, adherence to host cells, DNA uptake (competence), and protein secretion and that can act as nanowires carrying electric current. T4P are composed of a polymerized protein, pilin, and their assembly apparatuses share protein homologs with type II secretion systems in eubacteria and the fl...

The chemical composition of essential oils isolated from the leaves of Cosmos bipinnatus and its antibacterial activity were analyzed by GC-MS and microbroth dilution assay respectively. The essential oil extracted from this plant was predominantly composed of monoterpenes (69.62%) and sesquiterpenes (22.73%). The antibacterial assay showed that the oil had significant inhibitory effects agains...

A total of 451 strains of gram-positive bacteria were identified with a prototype of the Gram-Positive Identification card used in conjunction with the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.). Of the species that the Gram-Positive Identification card is capable of identifying, 85% of staphylococcal, 50% of beta-hemolytic group A, B, C, F, and G streptococcal, 91% of group D st...

At some point in the evolution of life, the domain Bacteria arose from prokaryotic progenitors. The cell that gave rise to the first bacterium has been given the name (among several other names) "last universal ancestor (LUA)". This cell had an extensive, well-developed suite of biochemical strategies that increased its ability to grow. The first bacterium is thought to have acquired a covering...

Bacteria are frequently exposed to a range of different circumstances in which the activation of adaptive mechanisms is essential for cell maintenance and survival. The modulation of such activity is intricately driven through gene regulation, involving diverse events at the transcriptional, translational, and posttranslational levels. Thus, transcription initiation could be considered the majo...

Fibrinogen (Fg), the major clotting protein in blood plasma, plays key roles in blood coagulation and thrombosis. In addition, this 340 kD glycoprotein is a stress inducible protein; its synthesis is dramatically upregulated during inflammation or under exposure to stress such systemic infections. This regulation of Fg expression indicates that Fg also participates in the host defense system ag...

We isolated a replication-thermosensitive mutant of the broad-host-range replicon pWV01. The mutant pVE6002 is fully thermosensitive above 35 degrees C in both gram-negative and gram-positive bacteria. Four clustered mutations were identified in the gene encoding the replication protein of pVE6002. The thermosensitive derivative of the related plasmid pE194 carries a mutation in the analogous r...

A group of nitrogen-containing steroids closely related in structure was screened for antibacterial activity, by use of Bacillus subtilis and Sarcina lutea as the test organisms. The most active compounds were cholesterol derivatives containing a tertiary or quaternary nitrogen in, or attached to, the A ring. Similar methyltestosterone or progesterone derivatives were inactive. All of the chole...

Despite similar clinical relevance of Gram-positive and Gram-negative infections, immune activation by Gram-positive bacteria is by far less well understood than immune activation by Gram-negative bacteria. Our group has made available highly purified lipoteichoic acids (LTA) as a key Gram-positive immunostimulatory component. We have characterized the reasons for lower potency of LTA compared ...

Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage. In order to understand their molecular mechanism and target cell specificity for Gram-positive bacteria, it is essential to consider the architecture of their cell envelopes. Before AMPs can interact with ...